N-1 DEB

N-1 DEB is a tracked piece of space debris attributed to Japan, launched on 1982-09-03 from TNSTA. With over 44 years in orbit, it has far exceeded many satellites’ design lifetimes. It orbits in Low Earth Orbit (LEO) at altitudes between 917 km and 1,159 km with an inclination of 44.6°. It travels at approximately 26,405 km/h (7.33 km/s), completing one full orbit every 106 minutes — that’s roughly 13.59 orbits per day. At its current altitude, the estimated orbital lifetime before atmospheric re-entry is ~500–1,000 years. As orbital debris, N-1 DEB poses a potential collision risk to operational satellites in nearby orbits and is continuously monitored by the U.S. Space Surveillance Network and other tracking systems.

N-1 DEB orbits at an average altitude of 1,038 km in the upper LEO band, where atmospheric drag is negligible and objects can persist for centuries to millennia. This altitude is used by broadband constellations like OneWeb and by scientific missions requiring stable orbits far from the densest debris bands. Within ±50 km of N-1 DEB’s average altitude, there are currently 183 active payloads and 501 tracked debris or rocket body fragments — notable neighbours include ONEWEB-0041. With an inclination of 44.6°, N-1 DEB passes over latitudes between 44.6°N and 44.6°S, covering the tropical and temperate zones where most of the world’s population resides. Low-to-mid inclination orbits are efficient to reach from equatorial and mid-latitude launch sites. Japan operates approximately 189 active satellites in total, of which 4 share a similar altitude band with N-1 DEB.